A plan for healthier oceans, healthier bodies

November 28, 2006|By John Balbus and Eliseo Guallar

WASHINGTON -- This month, a pivotal article published in Science magazine warned of the risk of depleting the world's seafood supply if current fishing practices remain unchanged. The article came on the heels of a long-awaited report from the Institute of Medicine calling attention to the health benefits of seafood and arguing that Americans should eat seafood for its abundance of lean protein and heart-healthy omega-3 fatty acids. How can we ensure these human health benefits with seafood stocks facing such a vulnerable future?

The booming fish farming industry - also known as aquaculture - can help and currently is the source of nearly half of the world's edible fish. In theory, aquaculture helps narrow the gap between declining global fisheries and increasing seafood demand. But the farmed fish highest in omega-3s are fed large quantities of fishmeal and fish oil, which in turn come from wild-caught fish. As a result, some aquaculture increases the demand for wild fish instead of reducing it. Conventional salmon farming, for example, requires approximately three pounds of wild-caught fish to produce a single pound of farmed salmon. The net result is further pressure on the world's fisheries.

The good news is that the oceans are capable of providing far more fish than they currently do. Unlike humans, fish do not stop growing at adulthood; their reproductive potential increases exponentially with age. For example, a single 10-year old female red snapper produces 9 million eggs annually, while a single 4-year old snapper produces less than one-two-hundredth that amount. Yet present fishery management policies allow too many fish to be taken too fast, without leaving enough large, highly reproductive females. Such systems encourage fishermen to maximize today's catch at the expense of future stock status and the health of the ecosystem.

Well-designed policies can effectively align fishermen's longer-term economic interests with the health of the ocean. For example, allocating fishermen a fixed percentage of the total allowable annual catch provides them an incentive to conserve; if the total allowable annual catch increases, so will the size (and value) of each fisherman's allocation. Such "catch share" programs are proving their worth in selected fisheries, such as Alaska's halibut fishery, where the fishing season has grown from a two-day derby to a 200-day season. Absent such policies, more and more fish stocks will crash, generating a negative-feedback cycle in which the dwindling number of remaining stocks will be more intensively fished until they crash as well.

Medical professionals and others who encourage the consumption of heart-healthy seafood have a vested interest in supporting sustainable fisheries policies that will make seafood abundant and affordable in the future. Doctors should communicate directly to patients about choosing eco-friendly seafood - for example, as identified on Web sites and wallet cards from Environmental Defense's Oceans Alive and the Monterey Bay Aquarium's Seafood Watch programs. And we can all make a difference by letting policymakers know that the long-term viability of fish stocks is important to the health of all Americans.

As recently noted in the American Journal of Preventive Medicine, "Eating fish may be good for health, but eating too many fish too fast is bad for the biosphere's health, and therefore, in due course, for people." With the public's help, policies can be adopted that are good for both people and the biosphere - and thus for many generations to come.

John Balbus is director of the health program at the nonprofit organization Environmental Defense. Eliseo Guallar is associate professor, Department of Epidemiology at the Johns Hopkins University Bloomberg School of Public Health.